Since a world update I have strange graphic problems like these under X Windows.
Not only with images but also with some GUI elements like menus (for example the firefox-bin menus are fine but the KDE-menus are shredded).

I've seen that the artefacts are always and only on the title bars of the windows.
So I've played around with the KDE settings and set
Desctop Effects -> Advanced -> Compositing type
from OpenGL to XRender .

Now I've no more artefacts.

EDIT:
I think the first very bad artefacts which disappeared with the older intel video driver have nothing to do with the smaller artefacts under KDE because they also appeared in twm...